1. Field
One or more aspects of embodiments of the present invention are directed to organic light-emitting devices.
2. Description of the Related Art
Organic light-emitting devices (OLEDs) are self-emitting devices that can provide multicolored images and that have wide viewing angles, good contrast, quick response time, high brightness, low driving voltage, and good response speed characteristics.
An OLED typically includes a first electrode on a substrate, and a hole transport region, an emission layer (EML), an electron transport region, and a second electrode sequentially formed on the first electrode. Holes injected from the first electrode move to the EML via the hole transport region, and electrons injected from the second electrode move to the EML via the electron transport region. When the carriers (i.e. holes and electrons) recombine in the EML, excitons are generated. When the excitons drop from an excited state to a ground state, light is emitted.